The systems, apparatuses and methods of the present invention set forth improvements to the problems of the current pairing or duplex paradigm, resulting in a dramatic increase in fiber transmission efficiency, accomplished explicitly by restructuring presently-aligned C-Band wavelengths into innovative DWDM transmit and receive formats, and through implementing photonic-wave changes, which directs Ethernet data flow onto new path adaptations. These improvements could reduce line haul expenses significantly, believed to reach a projected 50% less requirement/deployment of fiber strands. This saving would offer owner-operators substantial fiber strand cost reductions, affecting transportation rates of high-bandwidth digital payloads traversing over DWDM networks, and lower usage rates of cross-connections amid multiple equipment inter-exchanging throughout large data centers.

A bidirectional optical repeater having two unidirectional optical amplifiers and a supervisory optical circuit connected to optically couple the corresponding two optical paths through the repeater. In an example embodiment, the supervisory optical circuit is symmetrical in the sense that it enables the two optical input/output port pairs of the repeater to be interchangeable and functionally equivalent at least with respect to two supervisory wavelengths and some in-band and/or out-of-band wavelengths. This symmetry can advantageously be used, e.g., to improve the installation process directed at installing such optical repeaters in an undersea cable system. For example, a single directional orientation of the optical repeaters does not need to be maintained throughout the cable system, which can significantly reduce the risk and/or cost of installation errors.

A system and method for efficient optical signal amplification with system monitoring features are provided. For example, an optical repeater may include two different 4-port thin-film gain flattening filters (TF-GFFs), which may be connected to provide a high-loss loop-back (HLLB) path in the optical repeater for system monitoring. The 4-port TF-GFF may have four different ports and may integrate the functionalities of a conventional GFF and a coupler into a single component, thereby increasing power efficiency of the optical repeater.

The subject matter of the invention relates to a transmission method and system (100; 200) for improved unidirectional or bidirectional data transmission over a telecommunication network, a polarization attractor circuit (A1, A2; B1, B2), a computer program and a computer program product therefore.

A bidirectional optical repeater having two unidirectional optical amplifiers and a supervisory optical circuit connected to optically couple the optical ports thereof. In an example embodiment, the supervisory optical circuit provides one or more pathways therethrough for supervisory optical signals, each of these pathways having located therein a respective narrow band-pass optical filter. The supervisory optical circuit further provides one or more pathways therethrough configured to bypass the corresponding narrow band-pass optical filters in a manner that enables backscattered light of any wavelength to cross into the optical path that has therein the unidirectional optical amplifier directionally aligned with the propagation direction of the backscattered light.

In one embodiment, a switched amplifier is provided to amplify a data transmission. The switched amplifier may use a control signal that is received via a control signal channel in a transmission cable. Also, the switched amplifier may detect signal power to determine whether the data transmission is received at one of a first port and a second port. Data transmissions via the data transmission channel occur in a first direction and a second direction in a same frequency range in a time division multiplex (TDD) mode. Also, the control signal and data transmission are diverted from the transmission cable that transmits a type of signal different from the control signal and the data transmission. The switched amplifier is controlled based on the control signal or the signal power detected. The amplified signal is diverted in the first direction or the second direction via the data transmission channel back to the transmission cable.

In order to provide a compact and low power consumption optical repeater capable of amplifying a plurality of wavelength ranges, the optical repeater is provided with: an excitation means which generates excitation light in a single wavelength range; a first light amplification means which is excited by the excitation light and the amplification band of which is a first wavelength range; and a second light amplification means which is excited by the excitation light and the amplification band of which is a second wavelength range different from the first wavelength range.

A bidirectional optical transmission system includes a first optical transmission line including a first repeater (30A), a second optical transmission line including a second repeater (30B), and C+L band transmitting/receiving devices (10, 20) connected to each other through these transmission lines so that they can communicate with each other. The C+L band transmitting/receiving device (10) transmits an optical signal in a C-band to the first optical transmission line and transmits an optical signal in an L-band to the second optical transmission line, and the C+L band transmitting/receiving device (20) transmits an optical signal in the C-band to the second optical transmission line and transmits an optical signal in the L-band to the first optical transmission line. The first repeater (30A) separates the optical signal in the C-band and the optical signal in the L-band bidirectionally propagating through the first optical transmission line from each other, and separately amplifies the separated optical signals, and the second repeater (30B) separates the optical signal in the C-band and the optical signal in the L-band bidirectionally propagating through the second optical transmission line from each other, and separately amplifies the separated optical signals. In this way, it is possible to expand a transmission capacity and alleviate deterioration in a transmission characteristic.

In order to provide a compact and low power consumption optical repeater capable of amplifying a plurality of wavelength ranges, the optical repeater is provided with: an excitation means which generates excitation light in a single wavelength range; a first light amplification means which is excited by the excitation light and the amplification band of which is a first wavelength range; and a second light amplification means which is excited by the excitation light and the amplification band of which is a second wavelength range different from the first wavelength range.

The systems, apparatuses and methods of the present invention set forth improvements to the problems of the current pairing or duplex paradigm, resulting in a dramatic increase in fiber transmission efficiency, accomplished explicitly by restructuring presently-aligned C-Band wavelengths into innovative DWDM transmit and receive formats, and through implementing photonic-wave changes, which directs Ethernet data flow onto new path adaptations. These improvements could reduce line haul expenses significantly, believed to reach a projected 50% less requirement/deployment of fiber strands. This saving would offer owner-operators substantial fiber strand cost reductions, affecting transportation rates of high-bandwidth digital payloads traversing over DWDM networks, and lower usage rates of cross-connections amid multiple equipment inter-exchanging throughout large data centers.